Lonely Planet’s top 10 wacky roadside attractions in America

There is a sense of humour around every corner when you are driving in America. How else to explain those wacky, way-out-in-left-field roadside attractions you will stumble upon? Muffler men, mystery spots and antigravity hills are just the beginning. Here are our top 10 favourite offbeat spots.

1. Roswell, New Mexico: If you believe "The Truth is Out There", then the Roswell Incident is already filed away in your memory banks. In 1947, a mysterious object crashed at a nearby ranch. No one would have lost any sleep over it, but the military made a big to-do of hushing it up, and for a lot of people, that sealed it: the aliens had landed! International curiosity and local ingenuity have transformed the city into a quirky extraterrestrial-wannabe zone. Bulbous white heads glow atop the downtown street lamps.

Believers and kitsch-seekers should check out the International UFO Museum and Research Center (www.roswellufomuseum.com), which displays documents supporting the cover-up as well as lots of far-out art and exhibitions. The annual Roswell UFO Festival (www.roswellufofestival.com) beams down over the Fourth of July, with an otherworldly costume parade, guest speakers, workshops and concerts.

2. Salton Sea, California: California's largest lake in the middle of its biggest desert is an unexpected sight. After the Colorado River flooded in 1905, it took 1,500 workers and half a million tons of rock to put the river back on course. With no natural outlet, the artificial Salton Sea (www.saltonsea.ca.gov/) is here to stay. Its surface is 220ft below sea level and its waters 30% saltier than the Pacific.

Another unusual sight near the lake's eastern shore is Salvation Mountain (www.salvationmountain.us), a 100ft-high hill of concrete and hand-mixed adobe, covered with acrylic paint. With the motto "God Never Fails", it is the vision of folk artist Leonard Knight. Turn off Hwy 111 at Niland, drive east on Beal Road and you cannot miss it.

3. Cadillac Ranch, Texas: In 1974 the late, local eccentric millionaire Stanley Marsh planted 10 Cadillacs (vintage 1949 to 1963) headlights down in a deserted stretch of dirt outside Amarillo - and then moved them further out in 1997 because of town encroachment. The reason? He said he constructed what has come to be known as Cadillac Ranch (I-40 between exits 60 & 62) in a salute to Route 66, using cars he considered to represent the golden age of car travel. The accepted practice today is to leave your own mark on the art by drawing on the cars. Bring spray paint in case other visitors have not left any around. Occasionally the cars get a makeover, like when they were all painted pink in honour of breast-cancer awareness. To get here, park along the south feeder road, a couple of miles west of Loop 335, and walk the well-worn path.

The ground ̉around here seems to be fertile for growing cars - 18 miles east of Amarillo in Conway, there are five stripped-down VW bugs sprouting on Bug Ranch (Hwy 207 access road). The story goes that in 2002 the owners of a now-defunct convenience-souvenir store at the highway interchange wanted to attract customers, so they built the roadside attraction in parody of the classic Cadillac Ranch. It did not save the store, and the family has moved off, but the slug bugs in the dirt do attract attention. Again, feel free to leave your spray-painted signature. Both sights are visible from the 1-40 and accessible 24/7.

4. World's Largest Ball of Twine, Minnesota: There is much ado about which ball of twine actually holds the record these days. But why not pay your respects to the original that started all the fuss? Behold the World's Largest Ball of Twine in Darwin (www.darwintwineball.com), 62 miles west of Minneapolis on US 12. To be specific, it is the "Largest Built by One Person" - Francis A Johnson wrapped the 17,400lb whopper on his farm over the course of 29 years. Gawk at it in the town gazebo. Better yet, visit the museum beside it and buy your own twine ball starter kit in the gift shop.

5. Wall Drug, South Dakota: A tourist trap par excellence, this drugstore in South Dakota is famous for its roadside billboards that start advertising "free ice water" several states away, but it is a surprisingly worthy stop. They really do have 5 cent coffee, free ice water and enough diversions and come-ons to warm the heart of schlock-lovers everywhere. Do not miss the animatronic dinosaurs (www.walldrug.com).

6. Meteor Crater, Arizona: The second most impressive hole in Arizona was formed by a fiery meteor that screamed into the atmosphere about 50,000 years ago, when giant sloths lived in these parts. Meteor Crater (www.meteorcrater.com), 40 miles east of Flagstaff, is an out-of-this-world site for those with a thimbleful of imagination. Nearly a mile across and 600ft deep, there are lookout points around the crater's edge but no hiking to the bottom. Check out the fun, informative visitor centre.

7. Coral Castle, Florida: This favoured stop in Homestead is one man's kitschy do-it-yourself testament to lost love: Latvian immigrant Ed Leedskalnin dug up more than 2.2 million tons of coral rock to build this mock castle. Its engineering was once a bit of mystery, especially since the broken-hearted Romeo worked secretively at night without using any mortar. Some claim that the marvel has unusual electromagnetic properties. (www.coralcastle.com)

8. Lucy the Margate Elephant, New Jersey: Drive around the beach communities just south of Atlantic City and something massive, gray and kitsch will stop you in your tracks: Lucy the Margate Elephant (www.lucytheelephant.org), a 65ft-high wooden pachyderm constructed in 1881 as a developer's truly weird scheme to attract land buyers to the area. It was variously used as a hotel, beach cottage, private mansion and last, a tavern, but rowdy patrons almost destroyed her. Now recognized on the National Register of Historic Places, Lucy is open for tours during summer, starting every half hour, weather permitting.

9. Lucas, Kansas: "Outsider art", meaning works created outside the bounds of traditional culture, has blossomed in tiny Lucas. Samuel Dinsmoor began it all in 1907 by filling his yard with enormous concrete sculptures espousing his eccentric philosophies. His Garden of Eden is visible from the sidewalk, but paid admission lets you hear some wonderful stories and see his remains in a glass-topped coffin. (www.kansastravel.org/lucaskansas.htm)

10. Unclaimed Baggage Center, Alabama: Head into downtown Scottsboro on Hwy 279 and follow the signs to the Unclaimed Baggage Center (www.kansastravel.org/lucaskansas.htm). Wait...is that your iPod? The one you left in the seat pocket on that flight from Poughkeepsie? Probably. This Macy's-sized retail space is the end of the line for the majority of unclaimed bags in the US. After 90 days, the airlines send your lost luggage here. It takes thrift shop-level patience, but there is Tumi luggage, Kate Spade bags, Bruno Magli loafers, cameras, laptops, golf clubs - you name it - all for a fraction of retail.